Belt drive alignment detection device and method

ABSTRACT

A device ( 5 ) and a method for determining alignment of any component in a belt drive system ( 1 ) is disclosed. The device ( 5 ) is two sets ( 7, 8 ) of lines ( 9, 10 ) placed on separate carriers ( 11, 12 ). The second set ( 8 ) is placed over the first set ( 7 ) so that some of the lines ( 9, 10 ) are coincident. The second set ( 8 ) is secured to the first set ( 7 ) at one end of the device ( 5 ). To determine any misalignment, even minute misalignment, of the belt drive system ( 1 ) the device ( 5 ) is secured to the belt surface ( 6 ) of the drive belt system ( 1 ). The belt ( 4 ) is rotated until the device ( 5 ) is fed into a pulley ( 2 ). Any misalignement of the system ( 1 ) is visually indicated by the resulting misalignment of the lines ( 9, 10 ).

TECHNICAL FIELD

This invention relates to improvements in belt drive systems and moreparticularly to systems that employ a V-belt, or multiple V-belts. Thedisclosed invention is directed toward an efficient way to accuratelycheck the alignment of the components of a belt drive system.

BACKGROUND ART

Power transmission through belts or chains is most efficiently achievedwhen each component in the belt drive system is aligned in exactly thesame plane. Misaligned tracking of the belt over the drive pulleys andany idler pulleys results in excessive belt wear. Alignment of thediffering components optimizes belt drive system life.

Misalignment of the belt drive system, and the resulting non-linearmovement of the belt, may be caused by a plurality of reasons. Onereason is slack in the belt, generating lateral vibrations of the beltbetween the pulleys. This belt vibration as the belt travels about thedrive pulleys often causes the belt to become misaligned between thepulleys. Additionally, if there is excessive vibration in the entiredrive system, the belt may become misaligned.

Detection of initial and subsequent misalignment, even that of minutemisalignment, of any component of the belt drive system can improve thelife of the drive system, as well as reduce the belt drive noise.

U.S. Pat. No. 2,590,182 discloses providing a grooved idle pulley in abelt drive system to reduce lateral vibration of the belt as the belttravels between the drive pulleys. Other conventional methods tomaintain alignment of the belt include providing flanges on the drivepulleys. Belts formed with longitudinal teeth grooves on the undersideof the belt, corresponding to grooves in the pulleys may exhibit reducedmisalignment. These methods work to maintain a general alignment of thebelt between the pulleys, but do not provide a means for measuringminute misalignment of any component of the drive system.

Normal alignment procedures utilize some type of mechanical straightedge held against the pulleys or gears, for instance, a tautly pulledstring or a piece of angle iron. Measurements are often taken by twopeople due to the cumbersome nature of the method. After the measurementis taken, the straight edge is removed, adjustments are made to the beltdrive system, and the straight edge is repositioned to check thealignment. This procedure is repeated until alignment of the system isachieved.

U.S. Pat. No. 4,249,294 discloses an optical pulley alignment tool. Thedisclosed alignment tools consists of a first member and second membermounted on the pulleys inside the belt drive system. A target member hashorizontal and vertical alignment markings corresponding to thecenterline of the pulley. A viewing device having alignment markingscorresponding to the markings of the target member is mounted on thecenterline of the second pulley. Alignment of the pulleys is determinedby any alignment of the target markings and the alignment markings ofthe viewing device. When the markings of the target align in the viewingdevice, the pulleys will be in alignment in the horizontal, vertical andangular planes.

With the tool of U.S. Pat. No. 4,249,294, if the pulleys are inalignment, the belt is presumably in proper alignment. This assumptionmay hold true if the toothing on the belt and the pulleys permit littleto no lateral shifting of the belt. However, if the toothing grooves runacross the transverse direction of the belt, lateral displacement andmisalignment of the belt can still occur, absent any other mechanicaldevice to prevent belt movement.

The disclosed invention provides a quick and efficient means foraccurately determining alignment of the components of a belt drivesystem.

SUMMARY OF THE INVENTION

The purpose of this invention is to provide a device for ascertainingnon-linear movement of an object.

A further purpose is to provide an efficient way to accurately check thealignment of the components of a belt drive system.

A further purpose of the invention is a tool for accurately checking thealignment of the components of the belt drive system.

A further purpose of the invention is to provide a means for performingquick visual checks of the alignment of the components of the belt drivesystem.

A further purpose of the invention is a tool for efficiently checkingthe alignment of the components of the belt drive system.

The disclosed invention is achieved by two sets of identical series oflines disposed on two different carrier means. One set of lines is madeintegral with the belt, and the second set of lines overlays the firstset and is connected to the first set for a predetermined distance.

The belt and the predetermined distance of the device are fed into thepulley. The free end of the second, overlaying set of lines is free toshift with any misalignment of the drive system. Any misalignment of theany component of the belt system is quickly illustrated by thesubsequent misalignment of, or interference between, the two sets ofidentical series of lines.

BRIEF DESCRIPTION OF DRAWINGS

The invention will be described by way of example and with reference tothe accompanying drawings in which:

FIG. 1 illustrates a pulley and belt in a belt drive system with theattached disclosed device;

FIG. 2 illustrates one embodiment of the device;

FIG. 3 illustrates the device when indicating a small misalignment of acomponent of the pulley system;

FIG. 4 is illustrates the device when indicating a larger misalignmentof a component of the pulley system.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates a portion of a drive belt system 1. A belt 4 iswrapped about a drive pulley 2 which aides in moving the toothed belt 4in a direction indicated by the arrow T. In a typical drive belt system1, additional pulleys are present and the belt 4 may travel any pathselected by the engineer. The illustrated pulley 2 is provided withflanges 3 to maintain positioning of the belt 4; however, not allpulleys may be provided with such flanges 3. For a drive belt system 1to work at its optimum, all the pulleys should be in alignment and thereshould be no lateral movement of the belt 4; that is, each element ofthe belt drive system must be in alignment. Alignment of the pulleys isdetermined by the alignment of the centerlines of the pulleys. The beltcenterline is parallel to the pulley centerline, whether the parallelcenterlines are coincident or adjacent. To determine the alignment ofthe drive system components, the disclosed alignment device 5 is laid onthe belt surface 6 in a location visible to the operator or installer.

Illustrated in FIG. 2 is one embodiment of the device 5. The illustrateddevice 5 is two sets 7, 8 of identical series of parallel lines 9, 10disposed on carrier means 11, 12. The lines 9, 10 on each set 7, 8 aredistanced from each other, forming spaces 13, 14 between the lines 9,10. The width of the spaces 13, 14 is selected to provide a sufficientnumber of lines 9, 10 for easy visibility of the lines 9, 10 and spaces13, 14 therebetween. Too many lines will make it harder for the operatorto distinguish any misalignment in the belt drives system when using thedevice 5. The lines 9, 10 are distanced from each other by equal orvarying amounts.

The first set 7 is the bottom set and is made integral with the beltsurface 6 for measuring misalignment. The union of the first set 7 andthe belt 4 may be achieved in several ways. The first set 7 may bemarked as indicia on the belt surface 6, wherein the carrier 11 for thefirst set 7 is the belt surface 6. Alternatively, the first set 7 may beformed on a separate carrier 11, such as paper, plastic film, plasticsheet, or a metal strip, and then adhered to the belt surface 6 when analignment determination is desired. Adhesion to the belt surface 6 canbe done in a number of conventional methods such as providing clips orsimilar attachment means, or adhesive on the underside of the carrier11. The simplest technique is to use a carrier 11 with an adhesiveunderside which secures the set 7 to the belt surface 6.

For visibility of any misalignment of a drive belt component, the spaces13 between the lines 9 of the first set 7 may be formed in a visiblecolor which contrasts with the color of the lines 9. In conjunction withthe disclosed methods of forming the first set 7, this may beaccomplished in several methods. When the set 7 is formed as indicia onthe belt surface 6, the lines 9 are printed as a color which contrastswith the color of the belt surface 6, thereby creating a contrastbetween the lines 9 and the spaces 13. Alternatively, the set 7 may be aseparate pattern printed on the belt surface 6, and the lines 9 andspaces 13 formed in any desired contrasting colors. When the set 7 isformed on a carrier 11 other than the belt 4, any set of contrastingcolors which enable the lines 9 and spaces 13 to be quicklydistinguished from another is permissible. An example of such a colorcombination is black lines 9 and yellow spaces 13. The spaces 13 may beformed in multiple colors, forming greater contrast between the lines 9and the spaces 13.

For visibility of the lines 9 and spaces 13 of the first set 7, thesecond set 8 is on a transparent carrier 12 thereby forming transparentspaces 14. The lines 10 may be formed in any color other than a colorused for the spaces 13 of the first set 7, ideally the lines 10 are thesame color as that used for lines 9. The transparent carrier 14 may be astrip of transparent film or plastic sheet, or other similar material.

In forming the device 5 as a unit for determining alignment, the secondset 8 is laid over the first set 7, with the lines 10 of the second set8 being matched up precisely with the lines 9 of the first set 7, i.e.the lines 9, 10 are coincident, so that when viewed from overhead, itappears to be only one set of lines present. The second set 8 maybe'secured to the first set 7 along a select distance forming a securedend 15. Illustrated in FIGS. 3 and 4, the length of the secured end 15is approximately equal to 20% of the length of the device 5. The lengthof the secured end 15 may vary from at least 5% to 80% of the length ofthe device. At any selected percentage, the misalignment of anycomponent of the drive system is still visible.

The device 5 is employed as illustrated in FIG. 1 and as described inthe following manner. The device 5 is secured to the belt surface 6 asseen in FIG. 1. If the first set 7 is formed as an indicia on the beltsurface 6, the belt 4 is rotated to a point where the indicia is visibleto the operator. The belt 4 is driven into the pulley 2 so that thesecured end 15 of the device is also driven into the pulley 2. The freeend 16 of the second set 8 is free to shift with any misalignment. Anymisalignment of the any component of the belt system 1 is quicklyillustrated by the subsequent misalignment 17 of, or interferencebetween, the identical series of lines 9 and 10 of the two sets 7 and 8.

FIG. 3 illustrates a small misalignment wherein the free end 16 isskewed by a small degree. The resulting misalignment 17 is visible tothe operator, indicating a misalignment in the drive system 1. When thespaces 13 of the first set 7 are of a highly visible color, themisalignment 17 is quickly visible to the operator. FIG. 4 illustrates agreater misalignment of a component in the system 1 as rendered visibleby the misalignment 17 of the two sets of lines 9, 10 of the device 7.

The embodiment of the device 5 in FIG. 2 illustrated identical series ofequally spaced straight lines 9, 10. This is but one possible embodimentof the device 5. The criteria for the lines, in order to permit theoperator to determine any misalignment in the system, is that there are,on each set 7, 8, at least several lines 9, 10 which are initiallycoincident when the set 8 is laid over the first set 7 prior todetermining the system alignment and the configuration of the linespermits a visual indication of misalignment. Thus, the lines 9, 10 maybe present several different formats such as: the lines 9, 10 may becurved in any fashion, the lines 9, 10 may be present on the carriers11, 12 beyond the secured end 15, one set 7 or 8 may be provided withfewer lines than the other set 8 or 7.

Minute misalignment of the any component in the system that permits thebelt to enter a pulley in a misaligned orientation is quickly andaccurately rendered visible by means of the attached device 7. Thedisclosed device and method of determining any misalignment of thesystem will assist an operator or installer in rendering the drivesystem plumb to increase the life of the belt and the drive system, aswell as reduce noise and improve belt drive system efficiency. Thedisclosed device, while described in connection with a drive belt systemmay be used to determine any non-linear movement of a object wherein itis desired that the object move in a linear path.

What is claimed is:
 1. A device (5) for ascertaining non-linear movementof an object to which the device can be attached, the device (5) beingcharacterized by: a first and second set (7, 8) of lines, eachcomprising a series of lines (9, 10); the first set (7) being attachedto a first carrier (11); the second set (8) being attached to a secondtransparent carrier (12) and the second set (8) is placed over the firstset (7) in a manner capable of permitting both linear and non-linearmovement between the two sets (7, 8) with some of the lines of the firstset (9) and some of the lines of the second set (10) being coincident.2. A device (5) as set forth in claim 1 wherein the lines (9, 10) of thefirst and second sets (7, 8) are distanced by spaces (13, 14).
 3. Adevice (5) as set forth in claim 2 wherein the widths of the spaces (13,14) vary.
 4. A device (5) as set forth in claim 2 wherein the spaces(13) of the first set (7) are formed in a visible color.
 5. A device (5)as set forth in claim 1 wherein the first carrier (11) is selected fromamong the group of paper, plastic film, plastic sheet, a metal strip,and a belt surface (6).
 6. A device (5) as set forth in claim 1 or 5wherein the first carrier is the surface of a belt (6).
 7. A device (5)as set forth in claim 1 wherein the second set (8) is secured to thefirst set (7) at a first end (15) of the second set (8).
 8. A device (5)as set forth in claim 1 wherein the lines (9, 10) are straight orcurved.
 9. A device (5) as set forth in claim 1 wherein the lines (9,10) of each set (7, 8) extend the full length of the carrier (11, 12).10. A device (5) as set forth in claim 1 wherein the lines (9, 10) ofeach set (7, 8) are configured as straight parallel lines extending thefull length of each carrier (11, 12).